Diagnosis of toxoplasmosis in children with malignancy.

The study aimed at the diagnosis of toxoplasmosis in 73 children with malignancy; 31 with lymphoma (22 with Hodgkin's and 9 with non-Hodgkin's lymphoma) and 42 with leukemia (34 with acute lymphoblastic leukemia and 8 with acute myelogenic leukemia). In positive cases toxoplasmosis was manifested by any of the following; fever, lymph node enlargement, neurological manifestations and/or hepatosplenomegaly. The indirect hemagglutination test (IHA) for toxoplasmosis detected 4 (5.4%) positive cases with malignancy, 2 with Hodgkin's lymphoma, one with non-Hodgkin's lymphoma and one with acute lymphoblastic leukemia. The immunoglobulin M enzyme-linked immunosorbent assay (IgM ELISA) detected only one (1.4%) case with Hodgkin's lymphoma. Immunoglobulin G (IgG) ELISA detected 6 (8.2%) positive cases, 3 with Hodgkin's lymphoma, one with non-Hodgkin's lymphoma and 2 cases with acute lymphoblastic leukemia. Polymerase chain reaction for detection of parasite DNA in blood (PCR) was the most useful in diagnosing toxoplasmosis with malignancy, as it was able to detect 9 (12.3%) positive cases; 5 (6.8%) with Hodgkin's lymphoma, one (1.4%) with non-Hodgkin's lymphoma and 3 (4.1%) with acute lymphoblastic leukemia. No positive toxoplasmosis cases were detected with acute myelogenic leukemia by any of the above methods.